Multiple variants of blocking devices for the door of an automobile, also known as retaining devices, are currently known.
From among the known variants, the invention belongs to the type of devices of those comprising a housing which is traversed by a retaining rod, the housing being provided with brake members which, tensioned by a compression spring, are thrust towards the retaining rod. The brake members are generally provided with a contact surface intended to be applied, under pressure, against a corresponding face of the retaining rod, which is provided throughout its length with a series of recesses, in correspondence with the contact surface of the brake members, in which the brake members are fitted to offer a resistance to the sliding of the retaining rod through the housing. The mentioned housing is intended to be firmly assembled to the frame of a door or to the door, whereas the rod is fixed pivotably and at one of its ends to the component of the door in which the housing is not fixed, such that the opening or closing movement of the door causes the sliding of the retaining rod through the housing. In those positions in which the brake members stressed by the respective compression springs fit in the recesses of the retaining rod, the door tends to remain stable in an intermediate opening or closing position.
The objective of patent document EP 1588006 is a device which can be manufactured in a more cost-effective manner. Unlike other previous devices such as that described in document U.S. Pat. No. 6,842,943, formed by a hollow housing molded in plastic, which houses the brake members, requiring metal sheets for the compression of the springs previously introduced in the housing, the device described in EP 1588006 is formed by a first housing half and a second housing half which can be attached to one another, each limiting only one section of the contour of the opening for the passage of the retaining rod, in each of which there is housed a corresponding brake member tensioned by a respective spring towards the retaining rod which is supported directly on the bottom of the corresponding housing half.
The previously described device has some drawbacks, relating to the amount of material necessary for the formation of the two halves of the housing and with the supplementary means necessary for the attachment between the two halves of the housing, consisting of rivets.
In fact, the housings comprise respective boreholes for their fixing to the frame of the door or to the door of the vehicle, but the housings must necessarily be provided with respective projections, moved to a side of the cavity for guiding the brake member, for the arrangement of the boreholes. In addition to the increase in material, the points for anchoring the device are not centered or coincide with the longitudinal plane of the device, along which the brake members move, which causes a torque during the operation of the device caused by the thrust exerted by the retaining rod, which can bring about the loosening of the attachment of the housings to the vehicle looses.
In addition, the operation of insertion and further fixing of the rivets, as well as the cost of these components necessary for the attachment of the two housing halves do not precisely favor a reduction in the manufacturing cost. Furthermore, the time required to disassemble the device, for example to substitute the compression springs, is significant and it is not possible to perform this operation without destroying the components irreversibly attached by rivets.
Although patent document WO 2007031073 describes a variant which solves the problem of the location of the points for anchoring the device, it does not eliminate the drawback associated with the attachment between the two housing halves.
Document WO 2007057332 describes an alternative solution but lacking interest, due to the fact that it incorporates a metal sheet to attach the two housing halves to one another. For the handling of the mentioned sheet, and especially for bending it and introducing it into grooves provided for such purpose in the housing halves, tools are necessary and the operation is too time consuming to considerably reduce costs. Furthermore, incorporating metal closures which must necessarily be protected against corrosion generally involves a cost increase in comparison with the use of plastic components.
In the designs pursuing a split case solution such as those previously described, the fixing plane between the two housing halves cannot be assured due to the manufacturing tolerances, which can lead to a situation in which the brake members, guided only by their corresponding housing halves, are not perfectly aligned, causing noises, torque losses and low stability in a defined rest position.
A more cost-effective device, which represents a significant reduction in the assembly time, and which at the same time solves the aforementioned drawbacks, is therefore an objective of the present invention.